What's the main species of tree Andrew? The Poplar woodland around one of my patches is particularly uninspiring - until a Golden Oriole turns up that is. Likewise, I've visited Sycamore woodland that held few birds in winter/spring. I've just returned from Scotland, many of the conifer woods were deathly silent, though they should be livening up a bit now the weather's turned.
Probably the two main factors that will attract birds to this area are going to be suitable breeding habitat and availability of food. If you have these then I don't see why birds wouldn't be attracted to the area unless there are other factors involved which you haven't mentioned. Spring has only just sprung so give it time. It may be a completely different picture in a months time.
Recently started work at a place behind Stepping hill hospital, down the bottom of Bramhall Moor Lane. There is a small woodland behind my workplace, next to a large piece of open space, which I think is common ground. The thing is, apart from a few Magpies and Pidgeons, there is very little bird activity. The trees aren't showing any leaves yet, possibly because of the prolonged cold spell - would this have an effect on bird populations? I haven't even heard so much as a blackbird there and they are everywhere at the moment. Any ideas?